<!DOCTYPE html>
<html>
<head>
	<title>test</title>
	<style type="text/css">
		#out {
			width: 400px;
			height: 200px;
			margin: 10px auto;
			border: 1px solid black;
		}
		#inner{
			width: 100px;
			height: 100px;
			border: 1px solid red;
			margin-top: -10px;
		}
	</style>
</head>
<body>
	<div id="out">
		<div id="inner"></div>
	</div>

</body>
</html>